Fastener driving machine



1a. E. Mmmm" gpm@ FASTENER DRIVING MACHINE Filed Jan. 30, 194B 2 Sheets-Sheet E.

J. E. MERRTT FASTENER DRIVING MACHINE Mw ww 2 Sheets-Sheet 2 Jy M Filed Jan.

INVENTOR.

Wm RE N M@ Mm T w M J Patented May 2, 1950 UNITED STATES NT OFFICE d Claims.

This invention relates to tacking tools, and more particularly to a tack inserting tool of the type adapted to carry a length of wire from which the tack is cut while it is being driven by the tool.

A main object of the invention is to provide a novel and improved tack injecting and cutting device which is very simple in construction, easy to operate, and wherein, by a simple adjustment of the device, the operating stroke thereof may be regulated.

A further object of the invention is to provide an improved tack cutting and driving device which involves only a few parts, is rugged in construction and which is manipulated by simple downward pressure applied to the device, whereby tacks may be driven in rapid sequence and with e minimum amount of labor, and wherein the length of the tack may be adjusted as desired.

Further objects and advantages of the invention will become apparent from the following description and claims and from the accompanying drawings wherein:

Figure l is a side elevational view, partly in cross-section, of a tack injector constructed in accordance with the present invention.

Figure 2 is a vertical cross-sectional view taken through the central vertical plane of the tack injector of Figure 1 and showing the positions of the parts at the completion of a tack driving operation.

Figure 3 is a top plan view of the tack injector of Figure 1.

Figure 4 is a vertical cross-sectional View taken on line Ll-l of Figure 1.

Figure 5 is a horizontal cross-sectional view taken on line 5-5 of Figure 4.

Figure 6 is an enlarged detail perspective view of a wire guiding member employed in the tack injector of Figure 1.

Referring to the drawings, I I designates a generally tubular housing which is rectangular in cross-section and is formed at its bottom end with inwardly tapering walls terminating to define a reduced rectangular aperture l2 aligned with the vertical axis of housing II. Designated at I3, I3 are opposing convergent inner wall surfaces of said inwardly tapering bottom walls. Secured to the top end of housing I I is a flat rectangular cover plate Il, formed with a central aperture I5.

Slidably iitting in the lower portion of housing II is a hollow rectangular block or sleeve Iii and secured to opposing walls of said sleeve are spaced transverse pins ll, I I said pins being respectively parallel to the inclined surfaces i3, i3 being located in a common horizontal plane and being symmetrically spaced with respect to the vertical axis of housing Il. Pivotally mounted on said pins I l, Il are the respective lever arms I 3, I8 the lower ends of said lever arms being formed with opposed cutting jaws I9, I9 and the upper end portions of said arms being formed with outwardly offset elements 28, 2U. The outwardly ciset elements ZI), 29 are connected to the respective lever arms I 3, I 8 by downwardly and inwardly inclined opposing abutment portions 2i, il and carry at their top ends downwardly and inwardly inclined opposed lug elements 22, 22.

Slidably positioned in the housing II adjacent the oiiset elements 2B, 2! are vertical plate memers 23, 23' between which is secured a wedge block 211i, said offset elements being movably received between the plate members 23, 23' on opposite sides of the wedge block 2t. Wedge block 2li is formed at its bottom end with downwardly convergent wedge ssurfaces 25, 25.

When the lever arms I8, I8 are in the vertical positions shown in Figure 1, the downward inclination of the abutment portions 2l, 2| is somewhat greater than the downward inclination of the wedge surfaces 25, 25, as shown in Figure 1. When block 24 is moved downwardly into engagement with' abutment portions 2l, 2|, the block rotates arms I8, I8 outwardly to the positions shown in Figure 2 to equalize the inclinations oi the abutment portions i I. 2l with the inclinations of the wedge surfaces 25, 25.

Wedge block 24 is formed at its top end with downwardly convergent wedge surfaces 26, 26 adapted to wedgingly cooperate with the in clined lug elements 22, 22 responsive to upward force on wedge block 2d to urge the offset elements 211', 2t inwardly.

Wedge block 24 is formed with a vertical central bore 2i aligned with the vertical axis of housing II. A wire blank 28 is adapted to pass slidably through bore 28, said blank being inserted through the aperture I 5 in top cover plate I d.

At one side thereof adjacent its bottom end, housing l! is formed with an aperture 29, said aperture being formed with an inner shouldered seat at Sil. Formed in the opposing wall of housing il is a similar seat 3l. Designated at 32 is a plate member formed adjacent its ends with depending flanges 33 and 5d, said ends and flanges being adapted to be received in the respective seats 3l and 3e, as shown in Figure 4, whereby plate member 32 is supported in a horizontal transverse position in the lower portion of housing i i. A screw 35 is threaded through the shouldered portion of aperture 2@ and passes through an aperture it formed in flange 34, thereby locking the plate member 32 in said norizontal transverse position. Plate member 52 is formed with a central aperture El and secured to the bottom surface of said plate member adjacent the ilanges 33 and 3d are inwardly extending leaf springs 3u, 38 terminating beneath the aperture si.

The wire blank 23 passes through the aperture 'si of plate member 32 and is engagedby the opposing inner end edges of the leaf springs 38, causing said springs to be flexed downwardly, as shown in Figure e. The leaf springs thereby hold the wire blank against upward retr ctie-n but allow it to be moved downwardly by the action of jaws iii, le as will be presently described.

Adjacent plate member 23' the side wall of l housing i i is formed with. a vertical slot 3.9. Designated at lli is a handle member having a threaded stud 'oortion [5l which is slidably received said slot for Vertical movement therein and is threaded into plate member Z3'. Secured to the side wall of housing il below and parallel to movable handle member il? is a stationary handle member A strong coiled snring @il is seated at its ends in opposing recesses formed in handle members iii and l2 and biases handle member upwardly with respect to handle member fili.

Secured to the housing side wall above slot 39 is a luar tl and threaded through said lug is a vertical wing bolt which engages handle memmember il? therefore be regulated by suitably adiusting wing bolt 45.

Spring it normally maintains wedge block 24 in its raised position, shown in Figures l and 4. Since lug elements 22. bear on the tcp surfaces 2S, 2t of wedge block fl, sleeve lil is also held in a raised position by spring and the adjustment of wing screw also predetermines the starting position oi said sleeve member.

Bloch it is formed at opposite sides thereof with rectangular vertical recesses and positioned in each recess is a friction shoe Posh tioned between each shoe di and the inner wall surface of the associated recess le is a leaf spring :i8 which biases the shoe outwardly into frictional engagement with the inner wall surface of hcusing il, whereby a substantial force is required to move the block i vertically in the housing.

To operate the device, handle member iii? is forced downwardly toward handle member' d2. The wire end is at this time in engagement with the surface of the member into vwhich the tack is to be driven. As wedge block 2d comes into engagement with the abutment elementsli, 2i, the arms i3, it are rotated outwardly and the jaws is, lli are moved inwardly to grip the wire 23. Continued downward movement of wedge block 2li forces the jaws iii, iti into abutment with the surfaces l i3, the wire end being meanwhile driven into the underlying surface. The surfaces i il.- exert an inward wedging force on the jaws it?, i9 as downward movement of said jaws continues, as the jaws reach the aperture l2, the jaw edges substantially meet and shear off the wire substantiallyT ilush with the underlying surface, as shown in Figure 2. Handle member lili is then released, allowing spring t3 to expand.

This causes block 2li to move upwardly and releases the pressure on abutment elements 2l, 2l. The wire blank is held against upward movement by the leaf springs 33, 38 but the lever arms lil, i8 are free to be drawn upwardly since spring 43 strong enough to overcome the friotional force by the shoes Lil. As the top surfaces lit, engage the inclined lugs 22, 22 the lever are raised and at the same time rotated inwardly, restoring the parts to the starting positions shown in Figures l and 4. Since the setting of wing bolt li determines the starting position of handle member fill, the length of the downward stroke of lever arms it, ES may thereby be regulated, and hence the length or the tack ut from wire 28 may likewise be controlled.

While a specific embodiment of a tack forming driving tool has been disclosed in the foregoing description, it will be understood that varicus modiiieations within the spirit of the inma?,y occur to those skilled in the art. Thereiore, it 's intended that no limitations be the invention except as defined by the e appended claims. at is claimed is:

wardly and inwardly toward said aperture,

We member slidably positioned in the lower portion of said housing` a pair of opposing dy e cutting jaws pivoted to said sleeve inemld engageable with the downwardly and Aimrardiy sloping bottom wall surfaces of the housing, outwardly offset top arms carried by said cutting jaws, said top arms being formed dov-inwardly and inwardly extending abut-- ment surfaces, and a. block member slidably re- Yceived in the housing between said offset top arms and formed with downwardly inwardly inclined top surfaces wedgingly cocperable with s.. 1mitn'ient surfaces, said bl ck member beine" formed with a vertical bore through which the t. le blank passes downwardly towa jaws.

2. In a tack injecting tool of the type employing a wire blank for forming the .aacks,Y a tubular housing having a bottom wall formed with an aperture, the bottom wall surfaces sloping downwardly inwardly toward said aperture, a sleeve member slidably positioned in the lower portion of said housing, a pair of opposing lever pivoted to said sleeveV member, said arms being formed at their bottom ends with opnosed cutting jaws engageable with the downwardly and inwardly sloping bottom wall surface and at their upper portions with outwardly oiset elements, the top ends of said offset ele-- ments comprising downwardly and inwardly directed projections, a block member slidably received the housing between oir'set elements, the top or" said block member l.; formed with downwardly convergent wedge surfaces edgingly cooperable with said projections, said block member being formed with a vertical bore through which the wire passes,

means biasing' said block member upwardly into said aperture, a sleeve member slidably positioned in the lower portion of said housing, a pair of opposing lever arms pivoted to said sleeve member, said arms being formed at their bottom ends with opposed cutting jaws engageable with the downwardly and inwardly sloping bottom wall surface of the housing, said arms being formed at their top ends with outwardly offset elements, the top ends of said offset elements comprising downwardly and inwardly directed projections, a block member slidably received in the housing between said offset elements, the top of said block member being formed with downwardly convergent wedge surfaces wedgingly cooperable with said projections, means biasing the block member upwardly, said block member being formed with a vertical bore through which the wire blank passes, an apertured plate secured in the lower portion of the housing through which said wiie blank also passes, and downwardly and inwardly Idirected spring members carried by the end portions of said plate and engaging the wire blank on opposite sides thereof to oppose upward movement thereof and to limit the blank only to downward movement.

4. In a tack injecting tool of the type employing a wire blank for forming the tacks, a tubular housing having a bottom wall formed with an aperture through which the tacks are injected into a subadjacent surface, the bottom wall surfaces sloping downwardly and inwardly toward said aperture, a sleeve member slidably positioned in the lower portion of said housing, a pair of opposing lever arms pivoted in said sleeve member, said arms being formed at their bottom ends with opposed cutting jaws engageable with the downwardly and inwardly sloping bottom wall surface of the housing, said arms being formed at their top ends with outwardly offset elements, the top ends of said elements comprising downwardly and inwardly directed projections and the lower portions of said elements comprising downwardly and inwardly inclined abutments, a block member slidably received in the housing between said offset elements and formed to wedgingly cooperate with said projections responsive to upward movement of said block member and with said abutments responsive to downward movement thereof, means biasing said block member upwardly, said block member being formed with a vertical bore through which. the wire blank passes, an apertured plate secured in the housing subadjacent said sleeve member through which said wire blank also passes, and downwardly and inwardly directed leaf springs carried by the end portions of said plate and engaging the wire blank on opposite sides thereof to oppose upward movement thereof and to limit the blank only to downward movement.

JAMES E. MERRITT.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 752,305 Schubert Feb. 16, 1904 2,421,474 Alter June 3, 1947 

